This December, the Capitol has seen a trifecta of anniversaries including 150 years since Thomas Crawford’s “Statue of Freedom” was placed atop the Dome and 222 years since the first purchase toward the building of America’s temple of democracy.

And hidden from the Washington skyline, at the center of the city’s quadrants, equidistant between the Senate and House wings, is the campus’s most recent landmark. On Dec. 2, the 580,000-square-foot Capitol Visitor Center celebrated five years of open doors. In that time, the visitor center has given about 200,000 tours, welcomed 11 million callers and hosted 4,000 special events and meetings.

An average year brings as many as 3 million American and foreign tourists into the facility, where they can tour, interact with and gawk at the tapestry of history sprawled throughout the three floors of underground space.

The project began in 2000 as a quest to supplement existing space, but saw drastic changes that made designing a secure facility the priority following the 9/11 attacks.

In July 2008, construction was completed at a cost of $600 million, well over the initial $71 million envisioned.

“This was the ninth incremental growth of the Capitol. ... It must keep pace with a growing nation. What was perceived was a project doubling in cost, without making the distinction that it doubled in scale,” said Tom Fontana, the visitor center’s director of communications.

To meet the needs of Congress, 170,000 square feet was designated for private meeting rooms and a 450-seat theater.

While visitors are only permitted in one-third of the Capitol Visitor Center, the abundance of space means problems of the past, such as waiting in a line that stretches past the Supreme Court, are a thing of the 20th century.

As many as 12,000 visitors pass through the CVC every day.

“Of all the success stories of this building, and there are many, is the fact that we get people into a climate-controlled environment, even during the peak busy time, in an average of six to seven minutes. In years past, it could have been two hours and six minutes,” Fontana said.

Additionally, security is able to screen visitors in an area removed from the Capitol chambers. Another security measure was creating a subterranean loading dock for all trucks to be screened 1,000 feet away from the building.

More than 9,000 workers were involved in constructing the site. Laborers dug 65 feet down to clear 53,000 truckloads of earth on the East Side of the Capitol.

The entrance leads to a large wrap-around balcony, coated in 200,000 square feet of sandstone to match the original facade that in the 1800s was painted white to imitate the look of marble.

The center boasts a large Emancipation Hall named in honor of slave laborers who helped lay a foundation to the Capitol following the fire of 1814. A plaster version of the “Statue of Freedom” greets those entering Exhibition Hall, where 572 historic documents have been displayed through the years.

Guests can gaze at statues while picking up tour tickets in Emancipation Hall or pass through the alcove exhibitions that house models of the Capitol through its two centuries of existence.

Over the past two years, the center has also brought dignitaries from Brazil, Chile, Japan and Canada to study the facility as a model for similar projects.

The success is something Fontana is happy to see.

“It might have had its share of attacks during its construction but now it’s admired,” he said, referring to complaints during construction of its cost overruns.